How to Build a DIY Arduino Weather Station with Low Cost Sensors
Introduction
Building your own weather station with an Arduino is a fun and educational project that allows you to get hands-on experience with electronics and programming. With just a few inexpensive components, I was able to build a weather station that measures temperature, humidity, barometric pressure, and rainfall.
In this guide, I will walk through the entire process of assembling the hardware, wiring up the sensors, and writing the code to display and log the weather data. I'll also provide tips on how to improve and expand the project by adding additional sensors.
Required Components
To build the basic weather station, you will need:
-
Arduino Uno or compatible microcontroller - This serves as the brain of the weather station.
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Breadboard - For easily connecting the sensors and wires.
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Jumper wires - For making connections on the breadboard.
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DHT11 or DHT22 temperature and humidity sensor - Measures ambient temperature and relative humidity.
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BMP280 barometric pressure sensor - Measures atmospheric pressure, which can be used to forecast the weather.
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Rain gauge - Measures rainfall in mm.
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LCD screen - Displays the sensor readings.
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10K ohm resistors - Used with some of the sensors.
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Buttons - For interfacing with the LCD menu.
Optional Components
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Real-time clock module - Keeps accurate time for data logging.
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Anemometer - Measures wind speed.
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Wind vane - Measures wind direction.
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Light sensor - Measures light intensity.
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Servo motor - For controlling a wind vane.
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SD card module - Logs weather data to a storage card.
Assembling the Circuit
Here are the steps to assemble the circuit:
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Insert the Arduino into a breadboard.
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Connect the DHT22 sensor to 5V power, ground, and a data pin on the Arduino. I used a 10K ohm pull-up resistor on the data line.
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Connect the BMP280 pressure sensor to 3.3V power, ground, and the I2C pins on the Arduino.
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Connect the rain gauge to 5V power, ground, and a digital pin configured as an input.
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Connect the LCD screen to the appropriate pins on the Arduino. Follow the pinout for the specific LCD used.
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Connect buttons to control the LCD menu.
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Optional - Connect additional sensors like the real-time clock, anemometer, etc.
Carefully check all connections before powering on the Arduino!
Installing Required Libraries
To interface with the sensors, you'll need to install the following Arduino libraries:
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DHT Sensor Library - For the DHT temperature and humidity sensor.
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BMP280 - For the BMP280 pressure sensor.
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LiquidCrystal - For the LCD screen.
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Wire - For I2C communication.
To install a library, simply search for it in the Arduino IDE Library Manager.
Writing the Arduino Sketch
The Arduino sketch has the following key sections:
Declare Constants, Variables, and Objects
First, declare constants for the connected pins, variables to hold sensor data, and objects for the sensors and LCD.
```
const int DHTPIN = 2; // DHT22 data pin
const int RAINPIN = 3; // Rain gauge digital input
DHT dht(DHTPIN, DHTTYPE); // DHT22 object
BMP280 bmp280; // BMP280 object
LiquidCrystal lcd(RS, EN, D4, D5, D6, D7); //LCD object
float humidity;
float temperature;
float pressure;
```
Setup()
In setup(), initialize the sensors, LCD, and any other components. Also initialize serial communication for debugging.
```
void setup() {
Serial.begin(9600);
dht.begin();
bmp280.begin();
lcd.begin(16, 2);
}
```
Main Loop()
The loop() function runs continuously and reads the sensors, displays data on the LCD, and logs it to serial.
```
void loop() {
// Read DHT22
humidity = dht.readHumidity();
temperature = dht.readTemperature();
// Read BMP280
pressure = bmp280.readPressure();
// Print readings to LCD
lcd.setCursor(0,0);
lcd.print("Temp: ");
lcd.print(temperature);
lcd.setCursor(0,1);
lcd.print("Humidity: ");
lcd.print(humidity);
// Log to serial monitor
Serial.println(temperature);
Serial.println(humidity);
Serial.println(pressure);
// Small delay
delay(1000);
}
```
The full sketch brings together all the components into one program. Compile and upload it to the Arduino once complete.
Displaying Data on the LCD Screen
The LiquidCrystal library makes it easy to display sensor readings on the LCD. Some tips for the LCD menu:
-
Use
setCursor(col, row)
to position text on the screen. -
Check for button presses to navigate between screens.
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Display data on multiple screens like temperature, humidity, pressure, rainfall, etc.
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Format the display nicely using spaces and decimal points.
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Show statuses like "Measuring..." when taking readings.
With the LCD menu, you can cycle through all the weather data without needing to connect to a computer.
Logging Sensor Data
To log the sensor data over time, there are a couple options:
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Serial monitor - The easiest way is to print the readings to serial. View data by opening the serial monitor.
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SD card - For standalone logging, add an SD card module and log data to a CSV file.
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Computer - Connect via USB and log data directly to your computer. Requires coding a client application.
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Cloud platforms - For remote logging, connect a wifi module and push data to a cloud platform like ThingSpeak.
Logging allows you to collect long term weather records and analyze trends over time.
Enclosures and Mounting
For an outdoor weather station installation, the electronics need to be protected from the elements. Some options are:
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House the project in a weatherproof enclosure or electrical box.
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Seal any openings with silicone caulk.
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Use conduit fittings for cable entry points.
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Place desiccant packs inside to absorb moisture.
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Mount the enclosure high up on a pole or wall. Keep rain and snow off.
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Add lightning protection for electrical safety.
Properly enclosing the weather station will allow the electronics to operate reliably for years.
Expanding the Project
Some ways to enhance the weather station:
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Add an anemometer and wind vane to get wind speed and direction.
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Include a tipping bucket rain gauge for more accurate rainfall data.
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Incorporate air quality sensors like MQ-135 to measure gases.
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Build a weather proof enclosure with solar panel to run off-grid.
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Use a GSM module to text or email alerts and data.
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Leverage wifi to upload data to weather networks like WeatherUnderground.
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Design a mobile app to view live data from anywhere.
By mixing and matching sensors, there are tons of possibilities for customizing your weather station!
Conclusion
Building a DIY Arduino weather station is an enjoyable and educational electronics project. With just a handful of inexpensive components, you can start collecting your own local weather data. The modular design also makes it easy to add new sensors over time.
While it requires some basic programming and electronics skills, the end result is a cool project that provides useful environmental data at home. Just remember to properly enclose the components for outdoor use.
I hope this guide gives you a starting point for creating your own Arduino weather monitoring system. Let me know if you have any other questions!